1. Field of the Invention
The present invention relates to image processing, and more particularly relates to techniques for providing text and image selection from document images captured using a video camera.
2. Description of Related Art
Conventional word processor applications for the personal computer enable a user to select text or image portions within a document, corresponding to an electronically stored file, by means of button presses and dragging of a mouse cursor.
The situation is quite different when the displayed document is that captured by a document camera providing grayscale, and usually relatively low resolution, images, such as those employed in over-the-desk scanning systems. It is known to use, in such over-the-desk scanning systems, a video camera disposed above a desk to capture images of documents which are displayed to a user on a CRT monitor or other display device. More details of such systems are disclosed, for example, in EP-A-622,722 and British Patent Application 9614694.9. The capture of the document images may be for display in situ, or for transmission to a remote location as part of a videoconferencing tool.
However, a problem encountered with systems that capture images with a camera is how to provide a very efficient text selection interface for interactive face-up document camera scanning applications. There exits, therefore, a need for techniques that support the selection of rectangular regions of text and images within an image captured by the camera via a "click-and-drag" of the mouse defining two points, or a leading diagonal, and for techniques providing, in much the same way as a word processor interface, for single and multi-word text selection from such a document.